1. Field of the Invention
The present invention relates to a touch screen, and more particularly, to a signal processing circuit for processing an input signal provided from a touch screen in response to a driving signal and a signal processing system.
2. Description of the Related Art
A touch screen uses a driving signal to determine whether a user's touch occurs or not. A driving signal may be applied to the touch screen, the applied driving signal may be outputted through the touch screen, and whether or not a user touched the touch screen may be determined through change in the signal outputted from the touch screen.
The driving signal of the touch screen may be influenced by various noises. The noises which may influence the driving signal of the touch screen may include noise caused by a power supply voltage of a display panel, noise caused by an external lighting, noise caused by a user's finger and the like.
Such noises may be introduced into the touch screen, and the touch screen may output a signal containing noise.
When a signal containing noise is outputted from the touch screen, it becomes difficult to accurately determine changes of the signal. As a result, the noise makes it difficult to determine whether or not a user touched the touch screen.